function [flag] = Checker(lat1, lon1, lat2, lon2, data)
flag = 0;
if (lat1 > 90) || (lat1 < -90)
    warning('User latitude out of admitted boundaries [-90deg,+90deg]');
    flag = 1;
end
% if (lon1 > 180) || (lon1 < -180)
%     warning('User longitude out of admitted boundaries [-180deg,+180deg] (use "wrapTo180")');
%     flag = 1;
% end
if (lat2 > 90) || (lat2 < -90)
    warning('Satellite latitude out of admitted boundaries [-90deg,+90deg]');
    flag = 1;
end
% if (lon2 > 180) || (lon2 < -180)
%     warning('Satellite longitude out of admitted boundaries [-180deg,+180deg] (use "wrapTo180")');
%     flag = 1;
% end
if (data.mth > 12) || (data.mth < 1)
    warning('Invalid value for Month. mth = [1,12]');
    flag = 1;
end
if (data.UT < 0) || (data.UT > 24)
    warning('Invalid value for UT. UT = [0,24] (hours)');
    flag = 1;
end

end